Which agent is avoided during PCI due to risk of catheter thrombosis?

Which agent is avoided during PCI due to risk of catheter thrombosis?

• A. Unfractionated heparin
• B. Fondaparinux
• C. Enoxaparin
• D. Bivalirudin

Answer: (B)

During PCI you need anticoagulation that actively blocks thrombin generation at the catheter surface. Fondaparinux is a synthetic Xa inhibitor that works through antithrombin III, but it does not directly inhibit thrombin. In the catheter environment, thrombin can form rapidly, and without direct thrombin inhibition, clotting can occur on the catheter itself, leading to catheter thrombosis and impaired PCI success. This is why fondaparinux is avoided during PCI as the sole agent. If fondaparinux is used, an additional unfractionated heparin is often needed to provide thrombin inhibition, but the typical approach is to avoid using fondaparinux alone in PCI. Unfractionated heparin directly inhibits thrombin (and Xa), making it reliable during PCI, while bivalirudin directly inhibits thrombin and serves as an alternative; enoxaparin has antithrombotic effects but is not as effective as UFH for preventing catheter-related thrombosis during PCI.

During PCI you need anticoagulation that actively blocks thrombin generation at the catheter surface. Fondaparinux is a synthetic Xa inhibitor that works through antithrombin III, but it does not directly inhibit thrombin. In the catheter environment, thrombin can form rapidly, and without direct thrombin inhibition, clotting can occur on the catheter itself, leading to catheter thrombosis and impaired PCI success. This is why fondaparinux is avoided during PCI as the sole agent. If fondaparinux is used, an additional unfractionated heparin is often needed to provide thrombin inhibition, but the typical approach is to avoid using fondaparinux alone in PCI. Unfractionated heparin directly inhibits thrombin (and Xa), making it reliable during PCI, while bivalirudin directly inhibits thrombin and serves as an alternative; enoxaparin has antithrombotic effects but is not as effective as UFH for preventing catheter-related thrombosis during PCI.